Stress shielding
Stress shielding is the reduction in bone density as a result of removal of typical stress from the bone by an implant. This is because by Wolff's law, bone in a healthy person or animal remodels in response to the loads it is placed under.
When a distal implant is used, forces are transferred to the proximal parts of the bone, thus shielding the proximal part of the bone close to the joint, resulting in bone atrophy. A proximal implant reduces this effect by applying more stress to the proximal portion of the bone. However, this leads to high proximal peak loads. Ideally, stress is applied evenly over the whole implant. It is possible to mention the elastic modulus of magnesium compared to titanium, stainless steel, iron , or zinc, which makes it further analogous to the natural bone of the body and prevents stress shielding phenomena. Porous implantation is one typical alleviation method.